Measuring the Cold Spring Loop

I was going through some old email, and came across the following information regarding the measurement of the Cold Spring course and loop. I am indebted to Don Smith for this info, and I thought Bay State runners might find it useful.

Don writes:

In the fall of 2002, Richard Barton measured the loop at Cold Spring Park and found it to be: 101 yards (303 feet) short of 1.5 miles or 7617 feet = 1.4426 miles ~ 1.443 miles. Each 1/4 mile was marked with silver-gray paint (stripe) on trees about 3’ up from the ground. However, these are 1/4 mile points of the loop not the race course.

Thus, 2 loops = 2.886 = 2.89

On September 14 2003, I re-measured the Cold Springs Loop. The results of this measurement were 7568 feet = 1.4333 miles = 1.433

The difference between these two measurements is 49 feet or 0.6%. The accuracy of the wheel (see below) is about 50X better than this, so this is an indication of the amount of error introduced by walking the course. I tried to take the shortest route (the way a runner would probably go).

Averaging these two measurements gives us a good measure of the loop.

Therefore, 1 loop = 2.876/2 = 1.438 ± 0.005 miles
And 2 loops = 2.876 ± 0.010 miles

I also measured the start and finish portions of the Cold Springs Course twice. The results of these measurements are given below:

Start and finish portion = 1216 feet 10 inches = 0.230 ± 0.0025 miles

Adding these two measurements together gives us an accurate measurement for the entire course. These numbers are given below:

Full Course = 2.876 + 0.230 = 3.106 = ± 0.012 miles

= 3.11 ± 0.01 miles

Note: The measurement wheel used for these measurements is a 19” high precision wheel with a digital counter, which was calibrated over a mile distance at the Newton North High School track and found to be extremely accurate (to within 6-9 inches over a mile or ~ 0.015%). This translates to less than 3 feet over the 3.1 mile distance.

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Blogger's note: An additional problem with the CS course is that the upper loop on the field at the very start is not measured precisely and varies from meet to meet and season to season. The start is approximately even with the edge of the tennis court, but the curve around the field is generally set by Peter Martin by eyeballing it. I would guess this adds 2-3 seconds of uncertainty to the upper loop.